回答“rpm's get vey high no altitude”you have the wrong blades on. There should be 2 blades with a hole in the centre and 2 without the hole... This means the blades are working against each other. I has the same. As a last resort I read the instructions... they were very hard to find... you have to follow the link in the paper instructions (not particularly useful) -place the propellers with a hole in the middle on the motors with a protruding axle (front right and rear left motors); -place the propellers without a hole on the motors without protruding axle (front left and rear right motors).